Hypertension and cognitive function have been studied using measurements of brain volume. A decrease in brain volume can indicate shrinking. Studies have suggested that high blood pressure may be associated with reduced brain volume, which has been linked to impaired cognitive function. Researchers studied brain volumes using magnetic resonance imaging (MRI), and found that hypertension diagnosed in young and middle-aged adults was associated with smaller brain volumes. Those with early onset hypertension tend to have gray matter (the outermost layer of the brain), as well as white matter (the deeper tissues of the brain responsible for relaying information between brain regions) in their later years, around 45-80 years old.
